Posted for Bruce Hunter:
------------------------ From: Bruce Hunter <[email protected]> Subject: RE: EMC and Software Date: Tue, 2 Mar 1999 07:54:15 +1100 (EST) To: [email protected] Cc: [email protected] > On Mon, 1 Mar 1999 [email protected] wrote: > > > Sorry for not being clear: > > > > I have received and read a fair amount of data on the containment and > > recovery from ESD "spikes" through the use of software. > > > > Can software also control and/or limit the amount of emissions from > > equipment? Harmonics? Voltage variations? > > > > I know the question is broad and the answers may be "equipment specific". > > But when software and hardware design engineers get together on a design, > > are there any general "rules of thumb" or specifics that they should be > > aware of in terms of EMC? > > There are various software techniques to filters the effects of transients > and interference on input circuits with embedded software based products. > There range from averaging, successive sampling and comparison through to > signal analysis and recovery. > > One important rule of thumb is that software cannot recover information > where it doesn't exist. > > On the issue of ESD spikes, its seems that you are trying to recover from > a software crash induced by hardware susceptibility to transients. There > are various techniques that can be used from watchdog timers, program > boundary checking, cyclic reset and run operation etc. > > If the failure can result in a hazardous condition rather than an > unreliable product then you have a different and a more serious problem. > In this case you would need to establish and prove the safe operation of > this product by formal management of the functional safety of the product. > > You can look at IEC61508 (Functional safety of electrical/ electronic/ > programmable electronic safety related systems) for guidance here. Part 6 > of this standard has a good library of techniques to handle software and > hardware failures. UL1998 also has a list of useful measures to address > the results of hardware failures and malfunctions on software. > > I hope this helps... > > Bruce Hunter email: [email protected] > Thomson-CSF Pacific Phone: +61 2 9981 0630 Fax: +61 2 9971 1759 > 176 South Creek Road, Dee Why, NSW 2099, Australia > > ---------------End of Original Message----------------- -------------------------- Ed Price [email protected] Electromagnetic Compatibility Lab Cubic Defense Systems San Diego, CA. USA 619-505-2780 List-Post: [email protected] Date: 03/01/1999 Time: 13:01:59 -------------------------- --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to [email protected] with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to [email protected], [email protected], [email protected], or [email protected] (the list administrators).
